The present invention relates to a novel phthalocyanine compound. Also, the invention relates to an organic photoconductor and also a multilayer-type or monolayer-type organic photoconductor being used for, for example, copying machines, LD (laser diode) printers, LED (light emitting diode) printers, etc.
Phthalocyanine series compounds are known as pigments for a long time but recently these compounds are also being watched with keen interest as the materials responding to a near infrared light source having a long wavelength.
In particular, as the materials being used for organic photoconductors of copying machines, LD printers, LED printers, etc., utilizing a light source of a long wavelength of near 800 nm, such as a semiconductor laser and light emitting diode (LED) with the recent development of electronic industry, the phthalocyanine series compounds responding to these light sources being watched with keen interest.
In the preprints, Japan Hardcopy ""92, pages 153-156, 1992 Densi Shashin Gakkai (Electrophotographic Society), there is described a lecture gist entitled xe2x80x9cFormation and Properties of Titanyl Phthalocyanine Crystals containing Diol Compoundxe2x80x9d and in the preprints, Japan Hardcopy ""93, pages 659-662, 1993 Densi Shasin Gakkai (Electrophotographic Society), there is described a lecture gist entitled xe2x80x9cSyntheses and Properties of Titanyl Phthalocyanine new Polymorphsxe2x80x9d. Also, in JP-A-5-273775 (the term xe2x80x9cJP-Axe2x80x9d as used herein means an xe2x80x9cunexamined published Japanese patent applicationxe2x80x9d), there is described that a diol compound having one hydroxy group at each of two adjacent carbon atoms, such as, for example, 2,3-butanediol, etc., reacts with oxytitanium phthalocyanine at an addition ratio of 1:2 to form an addition compound and the possibility capable of being used for organic photoconductors, etc., is suggested.
As the material responding to a near infrared light source, a material having a light absorption at a longer wavelength region is preferred but in the compound obtained by reacting commercially available 2,3-butanediol as it is with titanyl phthalocyanine, there are problems that the absorption wavelength is not in a sufficiently long wavelength region, etc.
Furthermore, when a steroisomer group can exist in a diol compound such as 2,3-butanediol, by such a broad concept expression, it is unknown that a phthalocyanine compound is obtained by what kind of an isomer diol and for example, an organic photoconductor using a compound obtained by performing the reaction of meso-isomer diol and oxytitanium phthalocyanine has a fault that a sufficient sensitivity is not obtained.
When the present inventor has made various investigations under the circumstances described above, it has been discovered that the absorption wavelength of a reaction mixture of a diol compound having a specific isomer structure and an oxytitanium phthalocyanine compound and/or a di-substituted alkylene glycolate titanium phthalocyanine compound having a specific isomer structure, the compound being produced regardless of types of synthesis, exist in a long wavelength region and each of these compounds has selectively excellent absorption characteristics and that an organic photoconductor containing a reaction mixture of a diol compound having a specific isomer structure and an oxytitanium phthalocyanine compound and/or the foregoing di-substituted alkylene glycolate titanium phthalocyanine compound having the specific isomer structure has a selectively excellent sensitivity, and the present invention has been accomplished based on the discoveries.
That is, according to an aspect of the present invention, there is provided a reaction mixture of a threo-alkanediol having one hydroxy group at each of two adjacent carbon atoms thereof, said carbon atoms each being a secondary carbon atom, and an oxytitanium phthalocyanine compound.
According to other aspect of the present invention, there is provided a phthalocyanine compound represented by formula (I) 
wherein R1 and R2 each independently represents a substituted or unsubstituted alkyl group and Pc represents a substituted or unsubstituted phthalocyanine residue.
According to another aspect of the present invention, there is provided an organic photoconductor comprising the reaction mixture described above and/or the phthalocyanine compound described above.